Herbicidal derivatives of N-alkylpropanamides

ABSTRACT

A racemic or (d) form of compounds of the formula ##STR1## wherein X is alkyl optionally substituted by halogen, alkylsulfonyl, or halogen; R is an alkyl group and R 1  is the residue of an organic acid function, is useful as an herbicide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 855,104,filed Nov. 25, 1977 now abandoned which is a continuation-in-part ofSer. No. 826,214, filed Aug. 19, 1977, now abandoned.

FIELD OF THE INVENTION

The invention relates to new esters of certain N-alkylpropanamides,their use as herbicides and to herbicidal compositions containing theseesters.

SUMMARY OF THE INVENTION

The present invention is directed to new herbicidally effective estersof certain N-alkylpropanamides in a racemic or a (d) form and having theFormula I ##STR2## wherein X is (halo)alkyl, halogen, or alkylsulfonlyl;R is an alkyl group and R¹ is the residue of an organic acid function.

More particularly, the invention includes compounds of formula I whereinR is an alkyl group containing from 1 to 4 carbon atoms and R¹ is theresidue of an organic acid derived from carbonic acids ##STR3## in whichY is oxygen or sulfur or sulfonic acids -S(O)₂ -R² in which R² is analkyl group containing from 1 to 6 carbon atoms optionally substitutedby a halogen atom having an atomic number of from 9 to 35, inclusive, anaryl or an aralkyl group containing from 6 to 12 carbon atoms optionallysubstituted by from 1 to 5 nitro groups, alkyl or alkoxy groupscontaining from 1 to 4 carbon atoms and/or by halogen atoms having anatomic number from 9 to 35, inclusive; from aliphatic carboxylic orthiocarboxylic acids containing from 1 to 6 carbon atoms optionallysubstituted by 1 to 3 halogen atoms having an atomic number of from 9 to35, inclusive, or by a NO₂ group; from cycloaliphatic carboxylic orthiocarboxylic acids containing from 3 to 7 ring carbon atoms and atotal of 4 to 11 carbon atoms; from aromatic carboyxlic orthiocarboxylic acids containing from 6 to 12 carbon atoms optionallyring substituted by from 1 to 5 nitro groups, alkyl or alkoxy groupscontaining from 1 to 4 carbon atoms and/or by halogen atoms having anatomic number of from 9 to 35, inclusive; or from carbamic acids##STR4## in which Y is oxygen or sulfur and R³ and R⁴ are independentlya hydrogen atom or an alkyl group containing from 1 to 6 carbon atoms;and X is an alkyl group containing from 1 to 4 carbon atoms optionallysubstituted by from 1 to 3 halogen atoms having an atomic number of from9 to 35, inclusive; an alkylsulfonyl group in which the alkyl portioncontains from 1 to 4 carbon atoms or a halogen atom having an atomicnumber of from 9 to 35, inclusive.

Typical examples of compounds within the scope of the invention include:

N-(thioacetyloxy)-N-methyl-2-((-4-trifluoromethyl)-2,6-dinitrophenylamino)propanamide,

N-((propylsulfonyl)oxy)-N-methyl-2-(4-chloro-2,6-dinitrophenylamino)propanamide,

N-(ethoxythiocarbonyloxy)-N-methyl-2-((4-ethylsulfonyl)-2,6-dinitrophenylamino))propanamide,and

N-(methylthiocarbamoyloxy)-N-methyl-2-(4-propyl-2,6-dinitrophenylamino)propanamide.

It will be appreciated that the compounds of formula I have anasymmetric carbon atom and therefor can exhibit typical opticalisomerism. The (d) isomers and/or racemic mixtures of the compounds offormula I are herbicidally active and are included within the scope ofthe invention. Since the (1) isomers of the compounds of formula I havebeen found to be without useful herbicidal activity, it can be desirableto obtain the (d) form by separation from racemates or directpreparation for herbicidal use.

When R¹ is a group derived from a carbonic acid ##STR5## or sulfonicacid -S(O)₂ R², the alkyl group of R² can be straight- or branched-chainsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and thelike and halogenated derivatives thereof such as 2-chloroethyl,3-bromobutyl. R² can also be phenyl, benzyl, phenethyl, naphthyl or thelike and optionally ring-substituted derivatives thereof such as3,4-dichlorophenyl, 2-fluorobenzyl, 4-bromophenethyl, 2-methoxyphenyl orthe like. Generally, it is preferred to use carbonic acid derived groups##STR6## in which

R² is methyl or ethyl optionally substituted by a chlorine atom.Generally, it is preferred to use sulfonic acid derived groups -S(O)₂ R²in which R² is methyl, ethyl, or propyl optionally substituted by achlorine atom or is phenyl optionally ring-substituted by a methylgroup.

When R¹ is a group derived from an aliphatic carboxylic orthiocarboxylic acid, it can be derived from acetic, propionic, butyric,isovaleric, caproic, ethanthionic, propanthionic acid or the like andhalogenated derivatives thereof such as chloroactic, 3-bromobutanoic ornitroacetic acid and the like. Generally, it is preferred to use analiphatic carboxylic group derived from acetic or chloroactic acid.

When R¹ is a group derived from a cycloaliphatic carboxylic acid it canbe derived from cyclopropane-, 1-methylcyclopropane-,cyclopropylethane-, cyclobutane-carboxylic acid or the like. Generally,it is preferred to use a cycloaliphatic carboxylic acid group derivedfrom cyclopropane-, 1-methylcyclopropane- orcyclopropylethane-carboxylic acid.

When R¹ is a group derived from an aromatic carboxylic it can bebenzoic, phenylacetic, naphthoic acid or the like and ring-substitutedderivatives thereof such as 3,4-dichlorobenzoic, 2-fluorobenzoic,4-bromophenylacetic, 2-methoxybenzoic acid or the like. When thearomatic acid ia an aralkyl acid the alkyl portion is a straight-chain.

When R¹ is a group derived from a carbamic acid ##STR7## then R³ and R⁴are independently a hydrogen atom or an alkyl group containing from 1 to6 carbon atoms. Generally, it is preferred to use carbamic acid derivedgroups, ##STR8## in which R³ is a hydrogen atom and R⁴ is an alkyl groupcontaining from 1 to 3 carbon atoms.

The compounds of the invention are conveniently prepared from knownN-hydroxy-N-methyl-2-(2,6-dinitrophenylamino)propanamides by knownesterification techniques with a reactant containing the desired organicacid function for R'.

When the reactant containing the desired organic acid function isderived from an N-methylimidazole, then the reaction proceeds readily atroom temperatures in a relatively short period of time. Use of excessimidazole derived reactant increases the yield.

The product is easily recovered by known extraction techniques.

The compounds of the invention, have been found to be useful forcontrolling undesirable plant growth. That is, certain, members of theclass have been found to be herbicidally effective against a wide rangeof plant species. Others of the class are effective only against alimited number of plant species and are considered to be selectiveherbicides. Some of the compounds exhibit a high degree of herbicidalactivity in the control of a variety of economically important speciesof grasses and broad-leaved weeds. Some of the compounds areparticularly useful as selective herbicides for use in certain importantcrops.

The invention includes plant growth regulating compositions comprising acarrier or a surface-active agent, or both a carrier and asurface-active agent, and, as active ingredient, at least one compoundof Formula I. Likewise the invention also includes a method ofcontrolling plant growth which comprises applying to the locus aneffective amount of a compound of Formula I.

The term "carrier" as used herein means a solid or fluid material, whichmay be inorganic or organic and of synthetic or natural origin, withwhich the active compound is mixed or formulated to facilitate itsapplication to the plant, seed, soil or other object to be treated, orits storage, transport or handling.

Suitable solid carriers are natural and synthetic clays and silicatesfor example natural silicas such as diatomaceous earths; magnesiumsilicates, for example, talcs; magnesium aluminum silicates, forexample, attapulgites and vermiculites; aluminum silicates, for example,kaolinites, montmorillinites and micas; calcium carbonates; calciumsulfate; synthetic hydrated silicon oxides and synthetic calcium oraluminum silicates; elements such as for example, carbon and sulfur;natural and synthetic resins such as, for example, coumarone resins,polyvinyl chloride and styrene polymers and copolymers; solidpolychlorophenols; bitumen, waxes such as for example, beeswax, paraffinwax, and chlorinated mineral waxes; and solid fertilizers, for examplesuperphosphates.

Examples of suitable fluid carriers are water, alcohols, such as forexample, isopropanol, glycols; ketones such as for example, acetone,methyl ethyl ketone, methyl isobutyl ketone and cycohexanone; ethers;aromatic hydrocarbons such as for example, benzene, toluene and xylene;petroleum fractions such as for example, kerosene, light mineral oils;chlorinated hydrocarbons, such as for example, carbon tetrachloride,perchloroethylene, trichloroethane, including liquified normallyvaporous gaseous compounds. Mixtures of different liquids are oftensuitable.

The surface active agent may be an emulsifying agent or a dispersingagent or a wetting agent; it may be nonionic or ionic. Any of thesurface-active agents usually applied in formulating herbicides orinsecticides may be used. Examples of suitable surface-active agents arethe sodium or calcium salts of polyacrylic acids and lignin sulfonicacids; the condensation products of fatty acids or aliphatic amines oramides containing at least 12 carbon atoms in the molecule with ethyleneoxide and/or propylene oxide; fatty acid esters of glycerol, sorbitan,sucrose or pentaerythritol; condensates of these with ethylene oxideand/or propylene oxide; condensation products of fatty alcohols or alkylphenols for example p-octylphenol or p-octylcresol, with ethylene oxideand/or propylene oxide; sulfates or sulfonates of these condensationproducts, alkali or akaline earth metal salts, preferably sodium salts,or sulfuric or sulfonic acid esters containing at least 10 carbon atomsin the molecule, for example, sodium lauryl sulfate, sodium secondaryalkyl sulfonates, sodium salts of sulfonated castor oil, and sodiumalkylaryl sulfonates such as sodium dodecylenzene sulfonate; andpolymers of ethylene oxide and copolymers of ethylene oxide andpropylene oxide.

The compositions of the invention may be formulated as wettable powders,dusts, granules, solutions, emulsifiable concentrates, emulsions,suspension concentrates and aerosols. Wettable powders are usuallycompounded to contain 25, 50 or 75% by weight of toxicant and usuallycontain in addition to solid carrier, 3-10% by weight of a dispersingagent, 1-5% of a surface-active agent and where necessary, 0-10% byweight of stabilizer(s) and/or other additives such as penetrants orstickers. Dusts are usually formulated as a dust concentrate having asimilar composition to that of a wettable powder but without adispersant or surface-active agent, and are diluted in the field withfurther solid carrier to give a composition usually containing 1/2 - 10%by weight of toxicant. Granules are usually prepared to have a sizebetween 10 and 100 BS mesh (1.676- 0.152 mm), and may be manufactured byagglomeration or impregnation techniques. Generally granules willcontain 1/2-25% by weight toxicant and 0-10% by weight of additives suchas stabilizers, slow release modifiers and binding agents. Emulsifiableconcentrates usually contain, in addition to the solvent and, whennecessary, co-solvent, 10-50% weight per volume toxicant, 2-20% weightper volume emulsifiers and 0-20% weight per volume of appropriateadditives such as stabilizers, penetrants and corrosion inhibitors.Suspension concentrates are compounded so as to obtain a stable,non-sedimenting, flowable product and usually contain 10-75% toxicant,0.5-5% w of dispersing agents, 1-5% of surface-active agent, 0.1-10% wof suspending agents such as protective colloids and thixotropic agents,0-10% w of approprite additives such as defoamers, corrosion inhibitors,stabilizers, penetrants and stickers, and as carrier, water or anorganic liquid in which the toxicant is substantially insoluble; certainorganic solids or inorganic salts may be dissolved in the carrier toassist in preventing sedimentation or as antifreeze agents for water.

Aqueous dispersions and emulsions, for example, compositions obtained bydiluting a wettable powder or a concentrate according to the inventionwith water, also lie within the scope of the present invention. The saidemulsions may be of the water-in-oil or of the oil-in-water type, andmay have a thick mayonnaise-like consistency.

The compositions of the invention may also contain other ingredients,for example, other compounds possessing pesticidal, especiallyinsecticidal, acaricidal, herbicidal or fungicidal properties.

The method of applying the compounds of this invention comprisesapplying a compound of Formula I, ordinarily in a composition of one ofthe aforementioned types, to a locus or area to be protected fromundesirable plant growth such as the foliage of the plants or the plantgrowth medium, e.g., soil in which the plant is growing or is to begrown. The active compound, of course, is applied in amounts sufficientto exert the desired action.

The amount of compound of the invention to be used in controllingundesirable vegetation will naturally depend on the condition of thevegetation, the degree of activity desired, the formulation used, themode of application, the climate, the season of the year, and othervariables. Recommendations as to precise amounts, are, therefore, notpossible. In general, however, application to the locus to be protectedof from 0.1 to 10.0 pounds per acre of the compound used in thisinvention will be satisfactory.

EXAMPLES

The manner in which the compounds of this invention can be prepared isillustrated in the following examples, which demonstrate the preparationof typical species of the invention. In these examples, the identitiesof all compounds, intermediates and final, were confirmed by elementalanalysis, and infrared and nuclear magnetic spectral analyses. Theexamples are for the purpose of illustration only and should not beregarded as limiting the invention in any way.

EXAMPLE 1N-(acetyloxy)-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamide(1)

3 g of N-hydroxy-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamideand 0.82 g of N-acetyl-N'-methylimidazole were added to a stirredsuspension in 0.8 g of methylene chloride for 3 hours. The resultingmixture was poured into water. The methylene chloride layer was washed,dried over MgSO₄, and evaporated to give a yellow residue which wasrecrystallized from ethanol to yield 1.4 g (41% yield) of product; m.p.137-138° C., (d,1) isomer form.

EXAMPLE 2N-((methylsulfonyl)oxy-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamide

2.8 g ofN-hydroxy-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamide in 50ml methylene chloride was added at room temperature to a stirredsuspension of the product prepared from 1.4 g methane sulfonyl chlorideand 0.8 g N-methylimidazole. After 3 hours the resulting mixture waspoured into water. The methylene chloride layer was evaporated todryness and the residue was crystallized from ethanol to give a 0.8 g(22% yield) of product as a yellow solid; m.p. 145° C. withdecomposition, (d,1) isomer form.

EXAMPLE 3N-((methoxycarbonyl)oxy)-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamide

32 of N-hydroxy-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamideand the product prepared from 0.8 g N-methylimidazole and 0.9 g ofmethoxycarbonylchloride were reacted as a stirred suspension in 30 ml ofmethylene chloride for 3 hours. The resulting mixture was poured intowater. The methylene chloride layer was dried and evaporated to give 1.2g (33% yield) of yellow solid product, m.p. 112-113° C. (d,1) isomerform.

Further examples and repeated preparation of above compounds shows thatnearly quantitative yields are obtained when 2 mol equivalents of theimidazole acylating reagent are used.

The additional examples of compounds of formula I prepared by proceduressimilar to that of Example 1-3 are shown in Table I below. The compoundsare in the (d,1) isomer form unless otherwise indicated.

                  TABLE I                                                         ______________________________________                                         ##STR9##                                                                                                     Melting                                       Example                                                                              R      R.sup.1           Point; °C.                             ______________________________________                                        4      CH.sub.3                                                                              ##STR10##        151-152                                       5      CH.sub.3                                                                              ##STR11##        >129 (with decomposition)                     6      CH.sub.3                                                                             S(O).sub.2 C.sub.2 H.sub.5                                                                      118.9                                         7      CH.sub.3                                                                             S(O).sub.2 (CH.sub.2).sub.3 Cl                                                                   98-99                                        8      CH.sub.3                                                                              ##STR12##        110.5-112                                     9      CH.sub.3                                                                              ##STR13##        135-136                                       10     CH.sub.3                                                                              ##STR14##         98-100                                       11     CH.sub.3                                                                              ##STR15##        102-103                                       12     CH.sub.3                                                                              ##STR16##        156-157                                       13     CH.sub.3                                                                              ##STR17##        133-134                                       14     CH.sub.3                                                                              ##STR18##         91-92                                        15     CH.sub.3                                                                             S(O).sub.2 CH.sub.3 d-isomer                                                                    137-138                                       ______________________________________                                    

EXAMPLE OF HERBICIDAL ACTIVITY

The pre-emergence herbicidal activity of the compounds of the inventionwas evaluated by planting seeds of watergrass, garden cress, downeybrome, sicklepod and velvet leaf in test tubes, nominally measuring25×200 millimeters, containing soil treated with the test compound atthe rates of 0.1 and 1 mg per tube designated in Table I at Rates I andII, respectively. The planted soil was held under controlled conditionsof temperature, moisture, and light for 11 to 12 days. The amount ofgermination and growth in each tube were evaluated on a 0 to 9 scale, 0rating indicating no effect, 9 death of seedlings or no germination.

The post-emergence activity of the compounds of this invention wasevaluated by spraying 7-day old crabgrass plants, 10-day old pigweedplants, 6-day old downey brome plants, 7-day old sicklepod, 9-day oldvelvet leaf and 10-day old yellow foxtail plants to runoff with a liquidformulation of the test compound at the rates of 0.8 milliliter of an0.025% solution designated Rate I in Table I, and 0.8 milliliter of an0.25% solution designated Rate II in Table I. The sprayed plants wereheld under controlled conditions for 10 to 11 days and the effect of thetest compound was then evaluated visually, the results being rated onthe 0 to 9 scale described above.

The results of the pre- and post-emergence tests were summarized inTable II.

                                      TABLE II                                    __________________________________________________________________________    HERBICIDE SCREEN RESULTS                                                      Pre-Emergence (Soil)            Post-Emergence (Foliar)                             Water                                                                             Garden                                                                             Downey                                                                             Velvet                                                                            Yellow                                                                            Sickle-                                                                           Crab-                                                                             Pig-                                                                             Downey                                                                             Velvet                                                                            Yellow                                                                            Sickle-                         grass                                                                             Cress                                                                              Brome                                                                              Leaf                                                                              Foxtail                                                                           pod grass                                                                             weed                                                                             Brome                                                                              Leaf                                                                              Foxtail                                                                           pod                             I   I    I    I   I   I   I   I  I    I   I   I                         Example                                                                             II  II   II   II  II  II  II  II II   II  II  II                        __________________________________________________________________________    1     8   9    9    9   9   9   9   7  6    3   9   2                               9   9    9    9   9   9   9   9  9    8   9   9                         2     8   7    8    7   8   9   9   8  8    7   9   6                               8   9    8    7   8   9   9   9  9    9   9   8                         3     8   8    9    8   9   9   9   8  8    4   9   2                               8   9    9    9   9   9   9   9  9    8   9   9                         8     8   8    6    7   9   4   9   8  8    6   9   0                               9   9    9    9   9   8   9   9  9    9   9   0                         9     8   0    7    3   9   0   6   5  0    4   9   0                               7   0    9    4   9   0   8   5  0    4   9   0                         4     0   0    0    0   6   0   3   2  0    2   5   0                               4   0    5    0   8   0   3   4  0    4   7   0                         5     2   4    4    6   7   0   3   3  0    3   7   0                               7   4    9    6   9   0   9   9  4    7   8   0                         __________________________________________________________________________

In many instances the compounds of the invention possess a selectiveaction against weeds in crop plant cultures. For example, control ofgrasses and broadleaf weeds in cotton and sorghum crops can be achievedby a pre- or post-emergence application of such compounds of theinvention asN-(acetyloxy)-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)-propanamideandN-((methoxycarbonyl)oxy-N-methyl-2-(4-methyl-2,6-6-dinitrophenylamino)-propanamide.

I claim:
 1. A compound of the formula ##STR19## in which R² is an alkylgroup containing from 1 to 2 carbon atoms optionally substituted by achlorine atom.
 2. A compound according to claim 1 wherein R² is methyl.3. A compound according to claim 1 wherein R² is ethyl.
 4. A compoundaccording to claim 1 wherein R² is 2-chloroethyl.
 5. A herbicidalcomposition comprising a compound according to claim 1 and at least onesurface active agent or carrier therefor.
 6. A method for controllingundesirable plant growth at a locus which comprises applying to thelocus to be protected a herbicidally effective amount of a compoundaccording to claim 1 or a composition thereof.
 7. A method according toclaim 6 in which the herbicidally effective compound isN-((methoxycarbonyl)oxy)-N-methyl-2-(4-methyl-2,6-dinitrophenylamino)propanamide.